Envelope



' Nov. 30, 1965 YAM YEE 3,220,637

ENVELOPE Filed Aug. 28, 1964 2 Sheets-Sheet 1 70/77 ye e INVENTOR.

ATTOFNEVJ 7 Nov. 30, 1965 YAM YEE 3,220,637

ENVELOPE Filed Aug. 28, 1964 2 Sheets-Sheet 2 yam ye e INVENTOR.

United States Patent 3,220,637 ENVELOPE Yam Yee, 359 Tennessee Bldg, Houston, Tex. Filed Aug. 28, 1964, Ser. No. 392,695 2 Claims. (Cl. 229-76) This invention relates to a novel envelope. More particularly the invention relates to an envelope cut from a single blank of paper and having novel closing and securing means.

The art is prolix with numerous examples of envelopes which have attempted to solve the problem of providing a means for closing the envelope, which closing means would be secure against unauthorized and undetected opening and which at the same time would provide the necessary convenience in closing and using.

Moreover, it is desirable to have an envelope which is of simple construction and which can be easily folded to the desired shape to provide the necessary securing features as hereinafter specified. None of the prior art envelopes provide the convenience, security against undetected opening and ease of forming as does the instant invention.

It is therefore an object of this invention to provide an improved envelope which is easy to manufacture and which has novel closing and securing means.

Briefly stated, the envelope of this invention comprises a rectangular front panel having attached along the lower edge thereof a front panel extension. There is also provided a back panel substantially equal in dimensions with the front panel and attached along the upper edge of the front panel. The back panel is also provided with a back panel extension attached along the upper edge thereof, which in turn has attached thereto a closing flap adapted to be folded under the front panel extension in the closed position. The back panel is also provided with a pair of side flaps, one of which is attached to each end or side thereof. Each of the side flaps has attached on the upper edge or top a locking tab. When the envelope is closed, the front panel overlays the back panel, with the front panel extension being folded down over the top portion of the front panel. The side flaps are folded over the top of the front panel and the locking tabs are inserted underneath the front panel. With the envelope thus formed, the back panel extension is then folded down over the front panel extension and the closing tab is inserted underneath the front panel extension to thereby seal and close the envelope. In some embodiments of the invention the closing tab may be provided with adhesive on the upper or lower surface.

Reference to the drawings will further explain the invention wherein:

FIG. 1 is an isometric view of one form of the envelope of this invention shown in the closed position.

FIG. 2 is a laid out plan view of the cutout blank from which is envelope is formed.

FIG. 3 is an isometric view showing the envelope in a partially formed state.

FIG. 4 is an isometric view showing the envelope as it is folded or formed just prior to inserting a message there- Referring now to FIG. 2, the envelope of the instant invention is normally cut from a single sheet of paper in the form of blank 11, formed With front panel 12 which is generally rectangular in shape. Front panel 12 has attached along substantially the full length of the bottom or lower edge thereof a generally trapezoidal front panel eX- tension 13 as indicated by fold line 14. Back panel 15 is substantially equal in dimensions to the front panel 12 and is attached thereto along fold line 16.

Back panel extension 17, which is generally in the shape p 3,220,637 Patented Nov. 30, 1965 of an isosceles trapezoid, is attached to back panel 15 along the upper edge thereof at fold line 18. It will be observed that back panel extension 17 is attached along substantially the full upper edge of back panel 15, and the ends of back panel 17 are tapered upwardly whereby the upper edge of back panel extension 17 is of a shorter length than the lower edge of back panel extension 17.

Closing tab 19, which is likewise generally in the shape of an isosceles trapezoid, is attached to the upper edge of back panel extension 17 at fold line 20. Also, the lower edge of closing tab 19 as indicated by fold line 20 is of a shorter length than the opposite side thereof as indicated by marginal edge 21. It will also be observed that the upper or top edge of back panel extension 17 and the lower or bottom edge of closing tab 19 are of substantially the same dimension which, in certain forms of the invention, facilitates the folding and securing as will be explained hereinafter.

In some embodiments of the invention herein, closing tab 19 may be provided with a coating of adhesive either on the top surface or the bottom surface or on both surfaces. In addition, in certain embodiments front panel extension 13 may be provided with a coating of adhesive either on the top or bottom surfaces or both surfaces. It is to be understood that these adhesive coatings will generally be of the wettable type but may also be of the pressure sensitive type.

Each side of back panel 15 is also provided with a side flap 22, which flaps are attached at fold lines 25, and are generally in the shape of right triangles, and are adapted to fold over front panel 12 in the closed position. It may thus be stated that side flaps 22 are attached to back panel 15 at the base of the triangle.

Side flaps 22 each have attached along the upper edge thereof a generally trapezoidal locking tab 23 which is attached thereto along fold lines 24. It will be observed that fold lines 24 form the other leg of the triangles of flaps 22. Locking tabs 23 are adapted to be folded under front panel 12 in the closed position, and may, if desired, be adhered thereto by coatings of adhesive.

In forming the envelope from blank 11, front panel 12 is folded over back panel 12 along fold line 16 as shown in FIG. 3. Front panel extension 13 is then folded downwardly along fold line 14 and over front panel 12.

Side flaps 22 are folded along fold lines 25 so that side fiaps 22 overlay portions of front panel extension 13 and front panel 12. At this point locking tabs 23 are folded along fold lines 24 and are inserted under front panel 12 such that the envelope then has the form and shape as shown in FIG. 4.

At this point the envelope is ready for the insertion of a message or other material therein. When it is desired to close and secure the envelope, back panel extension 17 is then folded along fold line 18 such that back panel extension 17 overlays front panel extension 13 and portions of side flaps 22. Simultaneously, closing tab 19 is folded along fold line 20 and inserted under front panel extension 13, thus completing the envelope as shown in FIG. 1. As indicated above, closing tab 19 may be provided with adhesive coatings on the surfaces thereof, in which case the surfaces would be wetted or otherwise prepared for adhering the desired surfaces as indicated above.

In the closed position, as thus described, it will be observed that the envelope is very secure and cannot be easily or readily opened without tearing or mutilation thereof which would of course be easily detected as an unauthorized opening. Hence, there is provided an envelope which has greater security than prior art envelopes. Moreover, the particular configuration of closing tab 19 and the manner in which it locks under front panel extension 13 also adds to the security feature. Further, the

envelope of the instant inventi n is of simple construction and can be easily formed and closed.

Modifications may be made in the invention as particularly described without departing from the scope of the invention. Accordingly, the foregoing description is to be considered as illustrative only and is not to be construed asa limitation upon the invention as defined in the following claims.

What is claimed is:

1. ,An envelope formed of a single sheet of paper comprising:

a rectangular front panel,

a front panel extension attached along the lower edge of said front panel, r

a back panel substantially equal in dimensions to said front panel and attached thereto along the upper edge of said front panel,

a back panel extension generally in theshape of a trapezoid wherein the lower edge thereof which is attached to said back panel is of a longer dimension than the upper edge thereof,

a closing tab generally in the shape of a trapezoid.

wherein the lower edge thereof which is attached to said back panel extension is of a shorter dimension than the upper edge thereof, and which closingtab 25 is adaptedto fold under said front panel extension in the closed position,

a pair ofside fiapseach one of which is triangular in shape and attached at the base side thereof to each end of said back panel, and adapted to fold over said front panel, and

a pair of locking tabs, one of which is attached to the upper edge of each of said side flaps and adapted to fold under said front panel.

2. The envelope as claimed in claim 1 wherein:

said front panel extension is generally trapezoidal in shape and is attached to said front panel along substantially the full length thereof, and

said back panel extension is attached to said back panel along substantially the full length thereof, and

said closing tab is provided with adhesive on at least one surface thereof, and

the upper edge of said back panel extension is substantially the same length as the lower edge of said closing tab.

References Cited by the Examiner UNITED STATES PATENTS 180,199 7/1876 Chapman 229-82 1,135,064 4/1915 Shipley 229-s2 1,465,284 8/1923 Osenkowski 22984 FOREIGN PATENTS 723,493 1/1932 France.

GEORGE RALST ON, Primary Examiner. FRANKLlN T. GARRETT, Examiner. 

1. AN ENVELOPE FORMED OF A SINGLE SHEET OF PAPER COMPRISING: A RECTANGULAR FRONT PANEL, A FRONT PANEL EXTENSION ATTACHED ALONG THE LOWER EDGE OF SAID FRONT PANEL, A BACK PANEL SUBSTANTIALLY EQUAL IN DIMENSIONS TO SAID FRONT PANEL AND ATTACHED THERETO ALONG THE UPPER EDGE OF SAID FRONT PANEL, A BACK PANEL EXTENSION GENERALLY IN THE SHAPE OF A TRAPEZOID WHEREIN THE LOWER EDGE THEREOF WHICH IS ATTACHED TO SAID BACK PANEL IS OF A LONGER DIMENSION THAN THE UPPER EDGE THEREOF, A CLOSING TAB GENERALLY IN THE SHAPE OF A TRAPEZOID WHEREIN THE LOWER EDGE THEREOF WHICH IS ATTACHED TO SAID BACK PANEL EXTENSION IS OF A SHORTER DIMENSION THAN THE UPPER EDGE THEREOF, AND WHICH CLOSING TAB IS ADAPTED TO FOLD UNDER SAID FRONT PANEL EXTENSION IN THE CLOSED POSITION, A PAIR OF SIDE FLAPS EACH ONE OF WHICH IS TRIANGULAR IN SHAPE AND ATTACHED AT THE BASE SIDE THEREOF TO EACH END OF SAID BACK PANEL, AND ADAPTED TO FOLD OVER SAID FRONT PANEL, AND A PAIR OF LOCKING TABS, ONE OF WHICH IS ATTACHED TO THE UPPER EDGE OF EACH OF SAID SIDE FLAPS AND ADAPTED TO FOLD UNDER SAID FRONT PANEL. 